This is how I did this puzzle, I did not think it was very difficult.

Remember that the cages with 0x or 0/ must have a cell with the value 0.

1. a5 is not 0, refer to cage b4

2. a6 is not 0, refer to row 1 (b1 and e1 would be 0 if a6=0)

3. c5 is not 5, refer to cage c1 (cage c1 must have -1 in one of the cells)

4. a6 is not 1, refer to cage d6

5. c6 is not 0, refer to cage c3 (if c6=0 then d5=0 and that would leave no 0 for any cell in cage c3)

6. c6 is not 2, refer to rows 5&6, cage e5 would have no valid values.

7. c5 or d5 must be 2, that solves cell a5

From this point it is all basic steps to complete the puzzle.

I have created some images of the above steps if anybody is interested.
If anybody has any questions please feel free to ask, or if I made a mistake let me know.